// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)

#include "opengl_context_egl_wayland.h"

#include "common/error.h"

#include <dlfcn.h>

static const char* WAYLAND_EGL_MODNAME = "libwayland-egl.so.1";

OpenGLContextEGLWayland::OpenGLContextEGLWayland(const WindowInfo& wi) : OpenGLContextEGL(wi)
{
}

OpenGLContextEGLWayland::~OpenGLContextEGLWayland()
{
  if (m_wl_window)
    m_wl_egl_window_destroy(m_wl_window);
  if (m_wl_module)
    dlclose(m_wl_module);
}

std::unique_ptr<OpenGLContext> OpenGLContextEGLWayland::Create(const WindowInfo& wi,
                                                               std::span<const Version> versions_to_try, Error* error)
{
  std::unique_ptr<OpenGLContextEGLWayland> context = std::make_unique<OpenGLContextEGLWayland>(wi);
  if (!context->LoadModule(error) || !context->Initialize(versions_to_try, error))
    return nullptr;

  return context;
}

std::unique_ptr<OpenGLContext> OpenGLContextEGLWayland::CreateSharedContext(const WindowInfo& wi, Error* error)
{
  std::unique_ptr<OpenGLContextEGLWayland> context = std::make_unique<OpenGLContextEGLWayland>(wi);
  context->m_display = m_display;

  if (!context->LoadModule(error) || !context->CreateContextAndSurface(m_version, m_context, false))
    return nullptr;

  return context;
}

void OpenGLContextEGLWayland::ResizeSurface(u32 new_surface_width, u32 new_surface_height)
{
  if (m_wl_window)
    m_wl_egl_window_resize(m_wl_window, new_surface_width, new_surface_height, 0, 0);

  OpenGLContextEGL::ResizeSurface(new_surface_width, new_surface_height);
}

EGLDisplay OpenGLContextEGLWayland::GetPlatformDisplay(Error* error)
{
  EGLDisplay dpy = TryGetPlatformDisplay(EGL_PLATFORM_WAYLAND_KHR, "EGL_EXT_platform_wayland");
  if (dpy == EGL_NO_DISPLAY)
    dpy = GetFallbackDisplay(error);

  return dpy;
}

EGLSurface OpenGLContextEGLWayland::CreatePlatformSurface(EGLConfig config, void* win, Error* error)
{
  if (m_wl_window)
  {
    m_wl_egl_window_destroy(m_wl_window);
    m_wl_window = nullptr;
  }

  m_wl_window = m_wl_egl_window_create(static_cast<wl_surface*>(win), m_wi.surface_width, m_wi.surface_height);
  if (!m_wl_window)
  {
    Error::SetStringView(error, "wl_egl_window_create() failed");
    return EGL_NO_SURFACE;
  }

  EGLSurface surface = TryCreatePlatformSurface(config, m_wl_window, error);
  if (surface == EGL_NO_SURFACE)
  {
    surface = CreateFallbackSurface(config, m_wl_window, error);
    if (surface == EGL_NO_SURFACE)
    {
      m_wl_egl_window_destroy(m_wl_window);
      m_wl_window = nullptr;
    }
  }

  return surface;
}

bool OpenGLContextEGLWayland::LoadModule(Error* error)
{
  m_wl_module = dlopen(WAYLAND_EGL_MODNAME, RTLD_NOW | RTLD_GLOBAL);
  if (!m_wl_module)
  {
    const char* err = dlerror();
    Error::SetStringFmt(error, "Loading {} failed: {}", WAYLAND_EGL_MODNAME, err ? err : "<UNKNOWN>");
    return false;
  }

  m_wl_egl_window_create =
    reinterpret_cast<decltype(m_wl_egl_window_create)>(dlsym(m_wl_module, "wl_egl_window_create"));
  m_wl_egl_window_destroy =
    reinterpret_cast<decltype(m_wl_egl_window_destroy)>(dlsym(m_wl_module, "wl_egl_window_destroy"));
  m_wl_egl_window_resize =
    reinterpret_cast<decltype(m_wl_egl_window_resize)>(dlsym(m_wl_module, "wl_egl_window_resize"));
  if (!m_wl_egl_window_create || !m_wl_egl_window_destroy || !m_wl_egl_window_resize)
  {
    Error::SetStringFmt(error, "Failed to load one or more functions from {}.", WAYLAND_EGL_MODNAME);
    return false;
  }

  return true;
}
